Conventionally, a vehicle control is provided by utilizing map data in a navigation apparatus for suitably controlling a vehicle according to a road condition of a currently traveling road. For an accurate control of the vehicle, the map data in the navigation apparatus needs to be precisely prepared. However, the accuracy of the map data in the navigation apparatus is not sufficiently accurate for the requirement of the accurate control.
Therefore, techniques that store a trace of a travel of the vehicle as control information for controlling the vehicle are proposed. That is, for example, Japanese patent document JP-A-2005-121707 discloses an apparatus that is capable of matching a stored road shape in stored road information with a real road shape including a travel lane. The apparatus corrects the road information in a storage according to travel trace information derived from a travel of the vehicle on a road. That is, the apparatus corrects the road information in each of a travel direction of a road based on the travel trace information when the road information represents the road that is travelable bi-directionally as one road shape.
However, the road shape being handled in the above apparatus is a static object, thereby not changing for each travel of the vehicle on the road.
On the other hand, Japanese patent document JP-A-2006-3147 discloses a technique that records travel data of the vehicle such as vehicle speed that dynamically changes for each occasion of the travel. In the disclosure, a travel data output apparatus that can encourage a driver to drive the vehicle safely and in a fuel saving manner is described. The apparatus acquires route data and travel data of a certain route for storing it in a travel history database. Then, the route data of a currently traveled route is searched for in the database as the vehicle travels, for a display of travel data of the currently traveled road on a display unit in terms of fuel consumption, travel time, and average speed.
However, the travel data output apparatus does not mention a case where the same road is traveled for plural times. Therefore, a data storage area size for storing the travel data becomes very large if the travel data is stored separately for each day of travel.
Further, because the travel data is stored by a unit of travel route, the travel data is not handled appropriately even when travel data of plural travel routes has a redundant travel section. That is, the travel data is not examined in terms of same travel routes in the travel data.